Initially, level failures are a regular part of the experience and the only impact is that one life is lost and used boosters will not be refunded. Losing lives is nowadays just a minor nuisance. It is better to take a level failure than to use a booster. Thus, using boosters are a risky deal due to their former rarity and should only be used if a booster is already used, that you are close to completing the objective, or that the level is extremely difficult.